Equipment for planning the loading of cargo aircraft



E. KOLSCH 9 Sheets-Sheet 1 June 6, 1961 EQUIPMENT FoR PLANNING THELOADING oF CARGO AIRCRAFT Filed Aug. 2o, 1957 E. KOLISCH June 6, 1961EQUIPMENT FOR PLANNING THE LOADING OF CARGO AIRCRAFT 9 Sheets-Sheet -2Filed Aug. 20, 1957 INVENTOR. Eff/L KoL/scf/ E. KOLISCH June 6, 1961EQUIPMENT FOR PLANNING THE LOADING OF CARGO AIRCRAFT 9 Sheets-Sheet 3Filed Aug. 20, 1957 INVENTOR. EMIL KoLlscH E. KOLISCH June 6, 1961EQUIPMENT FOR PLANNING THE LOADING OF CARGO AIRCRAFT 9 Sheets-Sheet 4Filed Aug. 20, 1957 June 6, 1961 E. KoLlscH 2,987,254

EQUIPMENT FOR PLANNING THE LOADING OF CARGO AIRCRAFT- Filed Aug. 20,1957 9 Sheets-Sheet 5 Arron/VE Vs.

June 6, 1961 EQUIPMENT FoR PLANNING THE LOADING oF CARGO AIRCRAFT FiledAug. 20, 1957 E. KOLISCH 9 Sheets-Sheet 6 A7 7 ORA/75.

E, KOLISCH June 6, 1961 EQUIPMENT FOR PLANNING THE LOADING OF' CARGOAIRCRAFT Filed Aug. 20, 1957 June 6, 1961 E. KoLlscH 2,987,254

EQUIPMENT EoR PLANNING THE LOADING oE CARGO AIRCRAFT Filed Aug. 20, 19579 Sheets-Sheet 8 INVEN TOR. .L -Mn. KUL/5CH 6 F/G.// Y

3am, WfM

,4 fro RAM-Ks.

June 6, 1961 E. KOLISCH EQUIPMENT FOR PLANNING THE LOADING OF' CARGOAIRCRAFT Filed Aug. 20, 1957 3 f l 376 E www C) 0 fCG PL ANNER /P FIG.I4

9 Sheets-Sheet 9 INVENTOR.

EML KLISCH ArfpRA/Eys.

United States Patent O 2,987,254 EQUIPMENT FOR PLANNING THE LOADING FCARGO AIRCRAFT Emil Kolisch, New York, N.Y., assignor to ContinentalElectrolog Corp., a corporation of New York Filed Aug. 20, 1957Ser.. No.679,174 16 Claims. (Cl. 23S-1179) In order for an aircraft to takeA off,ily and land safely, the distance of its center of gravity along thelength of the aircraft from a fixed reference datum, must be at aposition somewhere between certain definite fixed limits which aregenerally determined by the manufacturer of the aircraft.

The unloaded weight of an aircraft, i.e., without crew, fuel, extraequipment or cargo, but including all standard equipment, is determinedgenerally by actually weighing the aircraft on a suitable weighing kit.The center of gravity position of the unloaded aircraft is determinedgenerally by utilizing suitable formulas in which the unloaded weight isa factor.

Assuming that the aircraft is to travel to a predetermined destinationrequiring a given fuel load, the weight of which is readilyascertainable, a specialist in the weights and balances division of theairport, taking into consideration the weight and center of gravityposition of the unloaded aircraft, as well as the weight ofthe crew,fuel and extra equipment and the location of such items, may determineby means of standard calculating devices well known in the art, theprimary operating -weight and primary operating center of gravityposition of the aircraft, i.e., the Weight and center of gravityposition of the aircraft loaded with all but cargo.

The payload or weight of cargo that can -be carried by the aircraft isof course the permissible gross take-off weight less the primaryoperating weight.

According to one present loading practice, the cargo loading supervisorattempts to distribute the available cargo load through the compartmentsor regions of the aircraft, so that the final center of gravity positionof the aircraft fully loaded with the available cargo, will fall withinthe permissible limits of the center of gravity.

As the loading proceeds, according to present loading practice, theweights of the successive items of cargo, generally indicated on eachitem by the shipper or manufacturer, and their position in the aircraftare noted on the manifest. After the aircraft has been loaded, themanifest is turned over to the weights and balances division of theairport Which determines the final or takeoff center of gravity positionof the aircraft as thus loaded. Should the final center of gravityposition thus determined be outside of the permissible limits of thecenter of gravity, the cargo loading supervisor will be advised that thecargo is improperly loaded and -must be shifted.

As the distribution of the cargo load requires estimation, computationsand reference to charts, some shifting of cargo may be required, howeverskilled the cargo loading supervisor, in order to correct inevitableerrors in loading. This is a very time-consuming and arduous procedureby reason of the diculty of manipulating heavy and bulky items of cargowithin the limited confines of the aircraft. In addition, each time thecargo is shifted, new calculations must be made to check for correctnessof the new distribution.

As a result of the foregoing, the take-off of the aircraft Will bedelayed with consequentv loss of efficiency due to reduction of flyingtime with consequent piling up of cargo in the warehouse.

Where the final or take-off center of gravity position Patented June 6,1961 ICC of the aircraft is determined by means of a specially designedslide rule, or computed by the use of a standard calculating machine, towhich the data from the manifest is transferred, the many manipulationsrequired in the use of such units are time-consuming. The calculationsmust accordingly be carefully checked and re'- checked for errors andeven with such checking and rechecking, there is no assurance that someerror has not remained undetected.

Where, in the attempt to eliminate the need for shifting of cargo,planning of the cargo distribution is done before loading and suchplanning involves the use of a slide rule or calculating machine, theproblems above noted render such planning operation time-consuming andsubject to error and such difficulties are aggravated when problems ofairdrops, off-loading and on-loading must be considered.

Where, after the aircraft is loaded and the center of gravity positionis determined to be within safe limits by resort to the slide rule orcalculating machine, as above pointed out, additional cargo must beloaded into the aircraft, the new center of gravity position must thenbe determined in the same manner as previously described with resultantdelay in the talee-oft` of the aircraft and Without assurance that errordoes not remain.

lt is accordingly among the objects of the invention to provide anautomatic computing equipment which is universally applicable by resortto simple manipulation, for use with any of various models, sizes andspecification of aircraft, which may readily and expeditiously beoperated to solve numerous problems including the determination of thedistribution of a given cargo load for a desired or take-olf finalcenter of gravity position,1 the checking of such planned loading of anaircraft to confirm that its center of gravity position falls withindesired limits, the re-checking of the loaded aircraft in the eventvfurther cargo is to be added, and the determination of the effects onthe center of `gravity position of airdrops, olf-loading, ori-loadingand the like, all without the need for calculations of any sort, or theconsultation of charts.

According to the invention from a broader aspect, the equipment hasfacilities whereby there may be manually set into the computations adesired sequence of compartments (not necessarily adjoining) throughwhich the cargo weight is to be distributed, whereupon the equipmentautomatically determines a distribution of the cargo weight through thecompartments of the sequence in such manner that the moment of the cargoto be loaded according to suchdistribution when added to the primaryoperating moment of the aircraft (moment of thev aircraft loaded withall but cargo) will equal the desired gross moment of the aircraft,which is the product of the desired take-olf center of 'gravity positionand the grossV take-off Weight of the aircraft, to attain substantiallythe desired final center of gravity position.

More specifically, the equipment determines the portion of the cargoWeight to be loaded into the rst compartment of a selected sequence ofcompartments having a predetermined load distribution pattern, so thatafter such portion is loaded, the ratio of the then remaining cargomoment divided by the remaining cargo weight is substantially equal tothe ratio of the sum of the moments of thev selectedrweight distributionpattern for the remaining compartments in the sequence divided by thelIllustratively, thevnose of the vaircraft is taken asV the referencedatum for the position of center of gravity and for length of momentarms, i.e., distancerto centroids of compartments, in all illustrationsthatfol'low.

sum of the selected weights for such compartments. This can be expressedby the formula:

RM=remaining moment RW=remaining weight.

vMF=moment of weight loaded into rst compartment AWF=weight loaded intofirst compartment vEM---Fzsum of moments of all compartments except rstcompartment 2W-F=sum of weights of all compartments except firstcompartment "Ihus, distribution of the cargo weight in all of theSelected sequence of compartments is to `be, effected proportionallyaccording toY the selected load distribution pattern substantially toattainv the desired center of gravity position. t

According to a `feature of the invention, the equipment ,compares theratio (S2-F) of the sum of the moments of all of the compartments in theselected sequence vless Ythe iirst compartment divided by the sum of theweights ,of-such compartments, to the ratio (SL) of the then remainingcargo moment divided by the then remaining cargo weight.

If VSL=.S2`,-F, it wouldV mean, referring to Formula I, that zerowei-ght would have to be loaded into the rst compartment to satisfy theformula. If SL S2-F, it would mean, referring to Formula I, that afinite weight could Vbe loaded into the first compartment, and the'equipment modifies the proportional load distributionfor thecompartment for which the load is being planned so that after suchmodied proportional load is set into the equipment for the initialcompartment or compartvv,ments of the sequence to be loaded, thereafterthe ratio Vof the then remaining moment to the then remaining weightwill substantially equal the ratio of the sum of the moments of theselected weight distribution pattern for the compartments of theselected sequence less the initial compartment or compartments, to thesum of the selected weight distribution pattern for such compartments,thereby to effect proportional distribution of the 'then remaining cargoweight to substantially achieve the desired final center of gravityposition of the aircraft.

If SL S2IF, referring to the Formula I, it would mean that the nalmoment of the aircraft, if any load was placed in the first compartment,and if all Vthe compartments in the selected sequence are used, would beless thantthat desired, if proportional loading was followed. I-fproportional loading was not followed, then some of the compartmentswould have very little weight load which might cause unequal bendingstress along the length of the aircraft which is undesirable.

lf SL S2-F, the first compartment in the selected rsequent is eliminatedlfrom the computations and the equipment willV thereupon automaticallyrecompute SE-F based on the remaining compartments in the sequence andthis procedure is thus repeated until SL= or S2-F for the remainingcompartments in the selected sequence.

If SL S2-F,. the modified proportional load for the rst compartment ofthe sequence will permit proportional distribution of the remaining loadinto the remaining compartments of the sequence for desired final centerof gravity. However, it is possible under such condition that a veryheavy load may be placed into the iirst compartment and relatively lightloads into the remaining compartments. This is undesirable as mechanicalstresses along the length of the aircraft may not be evenly distributed.t

According to another feature of the invention, the equipment has `meansto prevent an extreme deviation between a modified proportional loadgreater than proportional in the rst compartment and the proportionalloads in the remaining compartments.

vIt is to be noted that i-f the last compartment in the sequence shouldbe eliminated, as a relatively small weight would have a relativelygreat moment due to the arm of such last compartment, then the weight inthe first compartment would have to be reduced and distributed intocompartments more remote `from the reference datum to make up the momentlost by elimination of the last compartment. Hence, the proportionalweight distribution between the first compartment and the remainingcompartments might not be as extreme as if the last compartmentremained. Accordingly, the equipment compares SL to the ratio [S(E-L)]of the sum of the moments Vof the selected pattern of the compartmentsin the sequence less the last compartment, to `the, sum of the selectedweights of such compartments. If SL= S(2-'L), the equipment will modifythe proportional load distribution for the first compartmentas set forthabove. However, if SL S(2-L), the equipment indicates that the lastcompartment of the sequence should be eliminated from Vthe computationsthereafter and automatically recomputes the new .S2-L.

According to another feature, the equipment has facilities for changingthe load distribution pattern so that, for example, based upon thenature of the cargo to be loaded or the weight of the cargo, the portionof the cargo weight to be distributed in any compartment may be apredetermined proportion of the entire Acargo weight.

The equipment `also has facilities for determining whether the totalcargolweight can be loaded into the fseleeted compartments of thesequence without exceeding their total capacity and whether the plannedload for a compartment exceeds the Weight capacity of such compartmentand if so for indicating such weight capacity.

More specifically, facilities are provided for setting into thecomputation of the equipment:

(a) The primary weight of the aircraft (which for purposes ofillustration will be assumed to include the weight of the unloadedaircraft with its standard equipment plus Weight of crew, fuel Vandextra equipment, but without cargo);

, (b) The primary center of gravity position of the aircraft;

(c) The position of the desired nal center of gravity;

(d) The cargo weight to be carried; Y

(e) The planned weight yand preload Weight to be loaded into therespective compartments and preload stations ofthe aircraft; and

(f) A iixed position in each of thecompartments and a desired positionfor preload stations (illustratively the centroid of the respectivecompartments and preload stations). Y

The equipment has means to determine automatically:

(a) The desired gross moment of the aircraft as the product of thedesired final center of gravity position and .the gross weight (the sumof the primary weight and cargo weight);

(b) The moment of the planned load for each compartment and preload foreach station as the product of the planned load or preload and thecentroid position of the associated compartment or station;

(c) The primary moment of the aircraft as the product of the primaryweight and primary center of gravity position;

(d) The remaining moment, i.e., the difference between the desired grossmoment and the sum of the primary moment, and the accumulated preloadand cargo moments thus far planned;

(e) The remaining weight, i.e., the difference between -the cargo weightand the sum of the preload weights and those thus far planned for therespective compartments;

(f) The accumulated weights of primary weight plus preload weights andcargo weights planned, i.e., gross weight;

(s) The accumulated moments of primary weight plus preload weight andcargo weights planned, i.e., gross moment; and

(h) Center of gravity position based on (j) and (g).

More particularly, the primary Weight of the aircraft (Weight of theaircraft loaded with all but cargo) and the corresponding primary centerof gravity position are set into the equipment and the primary moment isdetermined. In addition, the cargo Weight to be carried and the desiredfinal center of gravity position are also set into the equipment.

The equipment will thereupon automatically compute the desired grossmoment of the aircraft, i.e., the product of the desired inal center ofgravity position and desired gross Weight of the aircraft (the sum ofthe primary Weight and the cargo Weight).

Thereupon, the equipment will automatically determine the remainingweight to be loaded into the aircraft, which is equal to the cargoweight less any preload and the amount (if any) of cargo weight thus farplanned for loading. At the start of the load planning such remainingweight is thus equal to the cargo weight less the Weight of any preloadset into the equipment and decreases as planned loads are set into theequipment.

In addition, the equipment Will determine the remaining momentcorresponding to such remaining weight, which is equal to the grossmoment less the sum of the primary moment, and the moments of anypreload and of the Weight thus far planned for loading, all of whichmoments are computed by the equipment. At the start of the loadplanning, such remaining moment is thus equal to the cargo moment lessany preload moment and decreases as planned loads are set into theequipment.

It is apparent that if the cargo weight is distributed through thecompartments of the aircraft so that the sum of the moments of suchcargo Weight when added to the sum of the primary moment, and preloadmoment, equals the gross moment, the desired tinal conditions of grossweight and gross moment will be achieved and hence the aircraft Willhave the desired final center of gravity position.

Assuming that the aircraft has n compartments to be loaded and there arepreloads, then the entire cargo weight, including preloads, must be sodistributed through said "n compartments, that the resultant sum of thecargo moments, based illustratively upon the centroids of the respectivecompartments and the centroids of the preloads, plus the primary moment,equals the desired gross moment.

In order to determine the distribution of cargo Weight into theaircraft, the Weight to be loaded into the rst compartment of thesequence is computed to be of such value that after it is loaded, theratio of the then remaining moment to the then remaining Weight willequal the ratio of the sum of the moments of the remaining compartmentsdivided by the sum ofthe weights of such compartments, i.e.,

(l) RM-MFZXM-F RW- WF Z W- F When this equality is achieved, then if theremaining cargo Weight, i.e., the cargo weight less the weight plannedfor the tirst compartment, is distributed through the remainingcompartments of the aircraft in the same proportion as the selectedgiven weights for such compartments, the cargo weight as thusdistributed for the entire aircraft will have a moment equal to theremaining moment and hence the desired final center of gravity positionof the loaded aircraft will be obtained.

Assuming that (a) MF=moment of weight to be loaded into rst compartment(b) WF=CL (computed load) =Weight to be loaded into rst compartment (7)CL=RW multiply by n" WF we have M 2 F CL m R W- RM (wr) WF MF Mz-FWm)vlnr-Jurkat:

then

(l0) CL= WFA-B- To illustrate a typical problem, assume that the primaryoperating weight of the aircraft (weight of aircraft loaded with all butcargo) is 22,700 pounds; the primary center of gravity is 200 inches;the cargo Weight is 9,300 pounds including a preload of 1,000 pounds atcentroid 380 inches and the desired nal center of gravity position is240 inches.

The illustrative aircraft yhas six compartments, B, C, D,

E, F and G with a selected given weight distribution (say' the maximumweight capacity) of 2,000, 5,000,5,000 4,000, 3,000 and 1,000 poundsrespectively, withthe oentroids of the compartments 200, 300, 350, 400,480 and 530 inches respectively.

The primary moment will thus be 4,540,000 inch pounds and the dmiredgross moment willrbe 7,680,000 inch pounds leaving a remaining moment of3,140,000 inch pounds to be satised by the distribution of cargo.

Loading the preload Weight of 1,000 pounds at centroid 380 inches willresult in a preload moment of 380,000 pounds. Hence, the new remainingmoment will be 2,760,000 inchv pounds and the new remaining weight willbe 8300, As the preload Voccupies compartment D in the illustrativeexample, the remainingcargo weight of 8300 pounds is to be distributedthrough some or'all of compartments B, C, E, vF and G. A

assegna.

The equipment determines which of such remaining compartments should beloaded for most uniform load distribution as previously set forth and inthe example herein'described, to `illustrate fthe invention,the'e'quipment'determines that, compartment G should not be loaded.

Accordingly, the weight of 8300 is to be distributed throughcompartments B, C, E, F.

Before computing the actual load distribution for the compartments,i.e., compartment B, for example, the equipment determines whether theweight to be computed would exceed the maximum capacityY of suchcompartment. Y l

To thisend,.snc,e CL or the computed weight for the compartment equals iAR it is apparent that if n AB -is greater than one, the product of ARWFA-B where WF equals the maximum capacity of the compartment, wouldexceed such maximum capacity. In the illustrative example, this is foundto be the case and YVthe equipment automatically indicatessuch maximumcapacity, -e- 2,000 pounds as the weight to be loaded into compartmentB.

Thereafter the equipments determining the weight (CL) for compartment C,based upon a remaining cargo weight of 6,300 pounds and a remainingcargo moment of 2,360,- 000 inch pounds.

Applying Formula to compute the load for compartments C and E, we nd CLto equal 2,800 and 2,000 respectively.

Since compartment F is the last compartment of the sequence to beloaded, the equipment automatically indicates the now remaining weightof 1,500 pounds to be loaded into this compartment which in theillustrative example will provide the desired iinal center of gravity.

This applicationisa continuation-impart of copending application SerialNo. 524,134, filed July 25, 1955, now Patent No. 2,901,171.

In the accompanying drawings in which are shown one or more of variouspossible embodiments of the several features of the invention,

FIG. 1 isa block diagram of the primary and desired condition circuit,

FIG. 2 is a diagrammatic view ofthe weight register, FIG.V 3'is..a viewof the arm register circuit,

FIGS. 4 and 5 are diagrammatic views of one of the l FIG. 11 is a,diagrammatic view of the AB storagel register,A j

sFlG. 12 is a diagrammatic view of the load director indicatu, Y Y Y eFIG.- 13isa ,diagrammatic view Vof thelcompartment selector circuit, andA Y Y WEIGHT REGISTER (FIGS. lVAND 2,)V

Referring now tothe drawings, the equipment comprises a weight register21 which, as shown in FIG.' 2, illusf tratively comprises three manuallyoperated switchesv 22, 23 and 24 related to units, tens and hundredsrespectively.

Each of the switches has ve banks A, B, C, D and E, each with ten xedcontacts, designated 0 and l through 9 respectively. A movable contactarm 25 associated with each of the banks is designed successively toengage the plurality of contacts and the contact arms 25 of the banks ofeach switch are ganged together to move in unison upon rotation of theassociated control knob 2,6.

The contacts 0 to 7 of banks A of each of the switches are connectedtogether by common lead 28 and thence by lead 29 to terminals TSU, TSTand TSH respectively of swtches 22, 23, 24. The contactsV 8 and 9 ofveach of the banks A are connected by common lead 31 to lead 32 which isconnected to terminals TAU, TAT and TAI-Iv respectively of the threeswitches.

The contacts 0 through 3 of banks B; 0, 1, 4 and 5 ofV banks C and 0, 2,4, 6 and 8 of banks D are connectedVv to lead 29. Contacts 4 through 9of banks B; contacts 2, 3, Y6 through 9 of banks C and contacts 1, 3, 5,7 and 9 of banks D are connected to lead 32. The contact arms 25 ofbanks A through D of switches 22, 23 and 24 are connected respectivelyto terminals TUS, TU4, I`U2, and TUI; TTS, TT4, 'ITZ and TTl; THS, TH4,THZ and TH1.

Connected between adjacent contacts 0 through 9 of banks E ofswitches22, 23 and 24 are weight resistors R1, R10 and` R100 respectively, i.e.,a resistor R1 is connected between contacts 1 and 2, etc. The contactarm 25 of bank E of switch 22 is connected to terminal TRW2, the contact0 of bank E of switch 22 is connected by lead 33 to the contact arm 25of bank E of switch'2'3; the contact 0 of bank E of switch 23 isconnected by lead 34 to the contact arm 25 of bank E of switch 24, andthe contact 0 of said bank E of switch 24 is connected to terminal TRWl.Thus, the resistors R1, R10, R100 are connected in series Vand form theweight resistor bank 35 (FIG. 4).

In Atheillustrative embodiment, each of the resistors R1` has a valueVofpone ohm, resistors R10 have a value often ohms and the resistors'R100have a value of one hundred ohms related to units, tens and hundredsrespectively.

ARM REGISTER (FIGS. 1 AND 3) VThe arm'register 41, shown in FIGS. 1 and3, is similarto the weight register (FIG.` 2)` except that it onlycontains the bank E and has three switches 42, 43 and 44 related tounits, tens and hundreds, each having a movable arm 25 controlled'by anassociated control knob 26. The resistors R1, R10 and R100 are connectedin series between terminals TRA2 and TRAl and form the arm resistor bank45 (FIG. 4).

The resistors R1, R10 and R100 of the arm register similarly have valuesof one ohm, ten ohms and one hundred ohms, respectively related tounits,.tens and hundreds.

POSITION SELECTOR SWITCH (FIG.'4)

i The equipment'includes a position selector switch 48, a portion ofwhich is shown in FIG. 4. This switch, which is manually operated -by acontrol knob 49, has -fve'banks A, B, C, D Vand E, each bankillustratively having ten liiXcd contacts, designated `PC Vfor, primarycondition, DC for desired condition, SL for station load,

B, C, D, E, F, G `Jfor the respective compartments and engaged by anassociated contact arm 51, said arms 5,1

9 being ganged together to move in unison upon rotation of control knob49.

All of the contacts of bank B, except the contacts DC and GC areconnected together by common lead 53 which is connected to terminal 54.The contact DC of bank B is connected by lead 55 to terminal 56 and bylead 57 to the contact GC of bank C. The contact GC of bank B isconnected to terminal 58. All of the contacts of bank C, except contactGC are connected by common lead 59 to terminal 61.

The contact DC of bank D is connected by lead 62 to terminal 54 and thecontact GC of bank D is connected to negative main N. The contacts PC,DC and SL of bank E are connected by common lead 64 to terminal 65; thecontacts B, C, D, E, F, and G of said bank are connected respectively toa switch arm 63 of an aircraft type selector switch 70, controlled byknob 71. The arms 63 are ganged to move in unison upon rotation of knob71 to engage 'either contact 70a or 70b in the illustrative embodimentshown. Connected to each of the contacts 70a is one end of an associatedixed resistor RBl, RC1, RDl, REI, RF1 and RGI, the other end of saidresistors being connected by common lead 66 to negative main N and alsoby said lead 66 to one end of xed resistor 68, which illustratively hasa value f l0 ohms, the other end of which is connected by lead 69 tocontact GC of bank E. The resistors RB1 through RG1 are the compartmentcentroid resistors for the associated compartments of the aircraft to beloaded, selected by the setting of switch 70, and are of value relatedto the distance of the centroid of the compartment from a iixedreference datum, the resistors being calibrated so that one ohm is equalto one inch. The resistors RBZ-RGz connected to contacts 70b are foranother type aircraft which may be selected by switch 70. The centroidresistors are preferably located in an adapter 75 (FIG. l), a separateadaptor desirably being provided for each type of aircraft.

The terminal 54 is connected to terminal TRWZ of the weight registerresistors 35 (FIGS. 2 and 4) the terminal TRW1 thereof being connectedto positive main P. The terminal 61 is connected to one end of a iixedresistor 72, illustratively of l0() ohms, the other end of which isconnected to negative main N. Terminal 56 is connected to terminal TR3,FIGS 4 and 6 of the gross weight accumulator 73W, hereinafter described,and terminal TR., of such gross weight accumulator 73W is connected bylead 74 to contact arm 51 of bank D of the selector switch 48. Thecontact arm 51 of bank A is connected to positive main P and contact GCis connected to terminal 76. The contact arms 51 of banks B and C of theselector switch are connected by leads 77 and 78 respectively' tojunction 79 to which is connected one side of a phase sensitiveamplifier unit 80 of conventional type. The other side of amplifier unit80 is connected to junction 81 which in turn is connected by lead 82 tothe contact arm 51 of bank E and also by lead 83 to terminal 84. Lead 66is also connected to terminal TRA! of the arm register (FIG. 3) and theterminal 65 is connected to terminal TRAZ of said arm register, theconnections above described defining a bridge B-l.

GROSS WEIGHT ACCUMULATOR AND PROGRAMMER (FIG. 6)

Referring now to FIG. 6 of the drawings, the gross weight programmer 85Wcomprises a stepping switch 91 having four banks A, B, C and D, eachwith an H or home position contact, and fourteen additional contacts1-14 designed to be successively engaged by an associated contact arm92, said contact arms 92 being ganged together to move in unison.

The gross weight accumulator 73W comprises three stepping switches 93,94, 95, each having three banks A, B and C each with eleven contactsdesignated H, l through v1l) designed to be successively engaged byganged 10 contact arms 96, 97, 98. The contact arm 92 of bank4 A ofstepping switch 91 is connected by lead 101 to one end of the coil 102of said stepping switch, the other end of said coil being connected toground. The contact arms 92 of banks B, C and D are connected by leads103 to one end of the coils 104 of stepping switches 93, 94, 95, theother ends of said coils being connected to ground. 'I'he steppingswitch 91 has two movable contact arms 105, 106, the former normallybeing spaced from fixed contact 105 and the latter normally engagingiixed contact 106 when coil 102 is not energized.

Each of the stepping switches 93, 94, 95 also has a movable contact arm107 which normally engages iixed contact 107' when the associated coil104 is not energized. Each of the stepping switches 91, 93, 94, 95 alsocontrols a cam C-1, C-2, C-3, C-4 which has a projecting portion 111normally engaging the end of a movable contact arm 112 to retain thelatter spaced from iixed contact 113 when the associated stepping switchis in the home position.

The gross weight programmer and accumulator 85W, 73W also includes threetransfer relays 115, 116 and 117, the relays 115, 116 each having threemovable contact arms 118, 119 and 121 normally spaced from fixedcontacts 118', 119 and 121 and the relay 117 has two movable contactarms 122 and 123 normally spaced from fixed contacts 122', 123. Themovable contact arms of each of the transfer relays 115, 116, 117 areganged together and adapted to move in unison upon energization of theassociated coil 125. In addition to the foregoing, a reset relay 126 isprovided having three movable contact arms 127, 128 and 129 normallyspaced from associated fixed contacts 127', 128 and 129 and a time delayrelay 131 is also provided, said relay 131 having a movable contact arm132 normally engaging xed con tact 132.

The H contact of stepping switch 91 is connected by lead 135 to thefixed contact 136 of start switch 137 which is automatically controlledby the multiplier A programmer 217 (FIGS. 1 and 5) hereinafterdescribed. The start switch 137 has another fixed contact 138 and across bar 139 is designed to engage the two iixed contacts to completethe circuit. The xed contact 138 is connected by lead 141 to positivemain P and by lead 142 to fixed contact 132 of time delay relay 131. Thecontact arm 132 of the time delay relay 131 is connected by lead 143 tocommon main 144 which connects the contacts l through 14 of steppingswitch 91. One end of the coil 145 of time delay relay 131 is connectedto ground and the other end of the coil is connected by lead 146 tomovable contact arm 10S of stepping switch 91. The associated iixedcontact 105 of said stepping switch 91 is connected by lead 147 topositive main P and by lead 148 to contact arm 106 and to fixed contact113 of cam C-1. The fixed contact 106 of stepping switch 91 is connectedby lead 151 to junction X and thence by lead 152 to fixed contacts 153of Add, Subtract, switch controls 154, 155.

The movable contact arms 156, 157 of the Add, Subtract switches areconnected respectively by lead 158 to terminals TAU, TAT and TAH and bylead 159 to terminals TSU, TST and TSH of banks A, B, C and D of weightresistor switches 22, 23, 24 respectively. In addition, lead 159 isconnected by lead 161 through normally closed switch 162 to contact l ofbank B of stepping switch 91.

Contact 2. of banks B, C and D of stepping switch 91 is connected byleads 165 to terminals TUI, TTI and THl, contacts 3 and 4 are connectedby leads 166 to terminals TU2, TT 2 and THZ, contacts 5 to 8 areconnected by leads 167 to terminals TU4, T1`4 and TH4 and contacts 9 andl0 are connected by lead 168 to terminals TUS, TTS and THS of weightregister switchesy 22, 23, 24 (FIG. 2).

The contact ll of bank 8 of stepping switch 91 is conapenas@ nected bylead: 171 to contact arm'119 of transfer relayY 115'.Y The contact llofbank C of stepping switch 91 is'connected by lead 172 toY contact'arm118 ofY relay 115. The contact 12 of bank C of stepping switch 91 isconnected by lead 173 to contact arm 119 ofrelay 116. The contact r12 ofbank D of stepping switch 91 is connected by lead 174 to contact arm 118of relay 116.

YThe contact 13 of bank D of stepping switch 91 is connected by lead 175to contact arm 122 of relay 117. The xed contacts 118', 119 of relay 115and 116 and the fixed contact 122 of relay 117 are connected by leads176 to common lead 177 which is connected to junction X. o

The movable contact arm 112 of cam C-l is connected by leads 181 and 182to the movable contactarme 121 of transfer relays 115, 116 and contactarm 123 of transfer relay 117. In addition, contact arm 112 of cam O-lis connected by leads 181, 183 to the contact arms 97 of banks BY ofstepping switches 93, 94, 95.

The contact 113 of cam C-1 is connected by lead 1875 to the contact arm186 of a reset switch 187, the associated xed contact 188 of which isconnected to one end of lthe c'oil 139 of reset relay 187, the other endof said coil being ,connectedv to ground. The contact arm 186 isconnected bylead 1917to the lixed contacts 127', 12S', 129 Vof relay126, the associated contact arms 127, 128, 129 of which are normallyspaced therefrom and connected by leads 193, 194, i195 to the contactarms 112 of cams C-2, C-3, C-4. The fixed contacts 113 of said cams C-2,C-,3 and C4 are connected by lead 196 to the movable contact arms 197 ofstepping switch 93, 94, 95, the associated iixed contact 107 of which isconnected by lead 197 to lead 103. Y

Each of the banks A, B and C of switches 93, 94, 95 has a home or Hcontact and ten individual contacts 1 through l as is clearlyk shown inthe drawings. Connected between the home contact and the iirst contactand the rst and second contact of each ofthe banksA of the switches 93,94, 95 up to and including the eighth to ninth contact, is a fixedresistor R1 having a value illustratively of one ohm, R-1 having, avalue of ten ohms and R460 havinga value of 100 ohms respectively.

The H contact Yof bank A of stepping switch 93 is connected to terminalTR3. The contact arm 96 of said bank A is connected by lead 261 to the Hcontact of bank A of steppingswitch 94; the contact arm'96 of said bankA is connected by lead 2192, to the I- I contact ofV bank A of `steppingswitch 95 and theV contact arm 96 of said bank A is connected toterminal TR4. Thus,

the resistors R-l, R-l, R-lti are connected in series and define thegross weight accumulator resistor bank 203 (FIG. 4).

The contact ofV each of the banks B of stepping switches 93, 94,` 95 isconnected by a lead 2135 to iixedV contacts 121', 123 and to one end ofthe coil 125 of the associated' relay 115, 116, 117, the other end ofsaid coils being connected to ground.

The gross moment programmer and accumulator 85M, 73M is substantiallyidenticalto the gross weight programmer and accumulator 85W, 73W, exceptthat it does not have bank C, and hence will not be described. Theremaining weight programmer and accumulator 85W', 73W Vand remainingmoment programmer and accumulator 85M', 73M are also substantiallyidentical to the gross weight accumulatonand .programmer 85W, 73W, bothdiffering from the gross weight programmer and accumulator in theconnections of the bank A of the associated stepping switches 93, 94, 95(FIG. l7)'and the remaining weight accumulator also has an additionalbank C.

f Thus, referring to FIG. 7, the terminal A'FR3 of theV remaining momentand remaining weight accumulator is connected by lead 267 to the contactarm 96 of bank yA ois/witch -931V 'The 10p contact of bank A isconnected byleae'zsm the contact arm" 96 of bank A uf switch' 94. The l0contact of bank A ofswitch 94 is connected by lead 209 to the contactarm 96 of bank A of switch: and the 10. contact of bank A of switch 95is connected to terminal TR4.

MULTIPLIER A BALANCING UNIT (FIG. 5)

` The multiplier A balancing unit 210 shown in FIG. 5 comprises threestepping switches 212, 213, 214 related to units, tens and hundredsrespectively. Each of the switches has six banks A, B, C, D, E and F,each with eleven xed contacts designated H, 0 and 1 through 9. A movablecontact arm 215 associated with each of the banks is designedsuccessively to engage the plurality of contacts and the contact arms ofthe banks of each switch are ganged to move in unison upon actuation ofthe coil 216 of each stepping switch. VOne end of each of said coils 216is connected to ground and the other end to multiplier A programmer unit217 designed to actuate the coils in predetermined timed relation in themanner hereinafterY set forth. As the operation of the programmerfunit217 is conventional, the circuit thereof will not be'described.

The contacts `0 9 of the bank A of each switch 212, 213 and 214 isconnected through an associated lamp 218 to ground and the contact armsof Vbanks A are connected by lead 219 to terminal 76 (FIG. 4). The lampserves as an indicator 220 of the center of gravity of the aircraft ininches.

The contacts H, 8 and 9 of banks B of stepping switches 212, 213, 214are connected together by common lead 221 and thencejby lead 222 toterminal TAU, TAT and TAH. The contacts 0, l through 7 of banks B areconfv nected by' common lead 223 and thence by lead 224 to terminal TSU,TST, TSH. The contacts H and 4 through 9 of banks C; H, 2, 3, 6-9 ofbank D and H, 1, 3, 5, 7 and 9 of bank E are connected to lead 222. Thecontacts 0, 1, 2, 3 of bank C; 0, 1, 4, 5 of bank D and V0, 2, 4, 6 and3 of bank E are connected to lead 224.

Connected between adjacent contacts 0 1, 1 2, etc. of banks E ofstepping switches 212, 213 and 214 are resistors R-l, R-10 and R-100related to units, tens and hundreds respectively, said resistors deiningthe multiplier A balancing resistors 225. The Contact H of each bank Fis connected by lead 227 to contact 9. The contact arm 215 of bankY F ofstepping switch 214 is connected by lead 228 to terminal 84 (FIG. 4).TheY O contact of said bankF is connected by lead 229 to the contactarm215 of bank E of stepping switch 213. The 0 contact of bank F ofstepping switch 213 is connected by lead 231 to the contact arm 215 ofbank F of steppingpswitch 212 and theV ,07 contact of bank F or"stepping switch 212 is connected by lead 232 to positive main P. c

LOAD kDETERMINATION UNIT (FIG. V9)

Referring to FIG. 9, the load determination unit` comprises a steppingswitch.251 which has seven banks A, B, C, D, E, F, G, each having ninecontacts H and l-8, designed to be successively engaged by thelassociated contact arm 252, the contact arms 252 of all of the banks,which normally engages the H contact being ganged 'together to move inunison.4

The contacts l, 4 and 5 of bank A are connected together by common lead253 and this lead is connected by lead 254 Vto terminal T4M. The contact2 of bank A lis connected by leads 255 and 256 to terminal TIM and byleadsz255 and 257 to contact 5 Yof bank E. The contact 3 of bank A isconnected by lead-258 to one end of xed resistor 259'the'other end ofwhich is connected by lead 261 to contact 3 of bank B. The contacts 6and 7 of bank A 'are tied togetherrand are connected by'rlead 262 toterminal'TRS of 'the -AR storage register 263 (FIG.V 10)"hereinaft'erdescribed, the terminal TRS of 13 bank B. The contact 8 of bank A isconnected to one end of Xed resistor 265, the other end of which isconnected by lead 266 to contact 8 of bank B. The contacts 1, 4 and 5 ofbank B are connected together by common lead 267 and thence connected bylead 268 to terminal T2M. The contact 2 of bank BY is connected by lead269 to terminal TSM.

The contacts 1, 4, 5, 7 and 8 of bank C are connected by common lead 273and lead 274 to terminal T4W. The contacts 2 and 3 of bank C areconnected by leads 275 and 276 to terminal T1W and by leads 275 and 277to contacts 5, 7 and 8 of bank G.

The contacts 1, 3, 4 and 5 of bank D are connected by lead 278 toterminal TZW. The contact 2 of bank D is connected by lead 279 toterminal TSW. The contacts 6 and 7 are connected by lead 281 to terminalTR6 of the AB storage register 282 (FIG. ll) and the terminal TRS ofsaid storage register is connected to negative main N. The contact 8 ofbank D is connected to one end of xed resistor 284, the other end ofwhich is connected to negative main N.

'I'he contact 4 of bank E is connected by lead 285 to terminal TR3 ofthe remaining moment accumulator 73M (FIGS. 7 and 9), the terminal TR4of said accumulator being connected to positive main P. Contact 4 ofbank E is also connected by leads 285 and 286 to contacts l and 2 ofbank F and the contacts 7 and 8 of bank E are connected to positive mainP.

The contact 3 of bank F is connected to one end of xed resistor 288, theother end of which is connected to positive main P. Contacts 4, 5, 7 and8 of bank F are connected by lead 289 to terminal 291 of the multiplierB balancing unit 292. The contact 6 of bank F is connected to one end ofxed resistor 293, the other end of which is connected to positive mainP.

Contacts 1, 2, 3 and 4 of bank G are connected by lead 294 to terminalTR3 of the remaining weight accumulator 73W (FIGS. 4 and 9), theterminal TR4 of which is connected to negative main N. Contact 6 of bankG is connected to one end of ixed resistor 295, the other end of whichis connected to negative main N.

The contact arm 252 of bank A is connected to positive main P and thecontact arm 252 of bank C is connected to negative main N. The contactarm 252 of bank B is connected by lead 296 to junction 297 and thecontact arm 252 of bank G is connected by lead 298 to junction 299 and aphase sensitive ampliier 301 is connected between junctions 297, 299.

The contact arms 252 of banks D and F are connected by leads 302, 303respectively to junctions 297, 299 and the contact arm 252 of bank E isconnected by lead 304 to terminal 305 of multiplier B balancing unit,the connections thus described defining a bridge B-2.

MULTIPLIER B BALANCING UNIT (FIG. 9)

The multiplier B balancing unit 292, shown in FIG. 9, comprises threestepping switches 307, 308 and 309 related to units, tens and hundreds,respectively. Each of the switches has four banks, banks A shown in FIG.9; Banks B shown in FIG. 10; banks C shown in FIG. l1 and bank D shownin FIG. 12, the latter bank being the indicating bank.

Each bank has 11 xed contacts designated H, 0 and 1 through 9respectively. A movable contact arm 311 associated with each of thebanks is designed successively to engage the plurality of contacts andthe contact alms of the banks of each switch are ganged to move inunison upon actuation of the coil 312 of each switch.

One end of each of said coils 312 is connected to ground and the otherend to multiplier B programmer unit 313 designed to actuate the coils inpredetermined timed relation in the manner hereinafter set forth. As theoperation of the programmer unit 313 is conventional, the circuitthereof will not be described.

Connected between adjacent contacts 0 1, 1 2, etc.

of banks A 'of stepping switches 307, 308, 309 are resis"i tors R-1, R10and R-100 related to units, tens and hundreds respectively, saidresistors defining the multiplier B balancing resistors 314. The contactH of each of the banks A is connected by lead 315 to contact 9 of theassociated bank. The contact arm 311 of bank A of stepping switch 309 isconnected by lead 316 to terminal 291. The zero contact of said bank Ais connected by lead 317 to the contact arm 311 of bank A of steppingSwitch 308. The zero contact of bank A of stepping switch 308 isconnected by lead 318 to the contact arm 311 of bank A of steppingswitch 307 and the zero contact of bank A of stepping switch 307 isconnected by lead 319 to terminal 305. The multiplier B programmer shownin FIG. 9 also controls the coil 321 of stepping switch 251 so that thelatter will be cycled in manner determined by the operation of themultiplier B programmer 313.

The banks B and C of the multiplier B balancing unit 292 control the ARand AB storage registers 263, 282 (FIGS. 10 and 11). Thus, referring toFIG. 10, the H and 9 contact of bank B are connected by lead 325. Thezero and 1 through 9 contacts of bank B of switches 307, 308, 309 areconnected by associated leads 326 to the corresponding contacts 0, 1through 9 of bank B of stepping switch 327, 328 and 329 of the ARstorage register 263. Each of the switches 327, 328, 329 has a bank Aalso with a 0 and 1 through 9 contact.

Connected between contacts 0 1, 1 2, etc., of the contacts of bank A ofswitches 327, 328, 329 are resistors R-l, R-10 and R100, related tounits, tens and hundreds, respectively, said resistors defining the ARstorage resistors 330. The banks A and B of stepping switch 327, 328,329 each has an associated contact arm 331, 332, the contact arms 331,332 of each of said switches being ganged to move in unison uponactuation of the coil 333 of the associated switch.

The contact arm 332 of banks B of each of the switches 327, 328, 329 isconnected to one end of an associated coil 334 of a relay 335, 336 and337, the other end of each of said coils being connected to ground. Eachof the relays 335, 336 and 337 has a movable contact arm 338 normallyengaging a fixed contact 339 when the relay is not energized. The fixedcontacts 339 of each of the relays 335, 336, 337 are connected togetherby common lead 341 which is connected to the contact arms 311 of blanksB of relays 307, 308, 309. In addition, said cornmon lead 341 isconnected to fixed contact 342 of AR switch 343, the movable contact arm344 of which is connected to positive main P.

The movable contact arm 338 of each of the relays 335, 336, 337 isconnected by lead 346 to the xed contact 347 of each of the steppingswitches 327, 328, 329, the movable contact arm 348 thereof normallyengaging the associated fixed contact and being connected to one end ofthe coil 333 of the associated relay, the other end of said coil beingconnected to ground.

As is clearly shown in FIG. l0, the terminal TRS of the R storageregister 263 is connected by lead 349 to the 0 contact of bank A ofswitch 329. The contact yarm 331 of said bank A is connected by lead 351to the zero contact of bank A of switch 328. The contact arm 331 of bankA of switch 328 is connected by lead 352 to the zero contact of bank Aof switch 327 and the contact arm 331 of said bank A of switch 327 isconnected by lead 353 to terminal TR6.

As the circuits for banks C of switches 307, 308, 309 and the AB storageregister shown in FIG. 11 are identi cal to the circuits for banks B andthe AR storage register shown in FIG. 10, they will not be described,the corresponding elements having the same reference numerals.

The indicating bank D shown in FIG. 12 has its contacts 0 and 1-9connected by leads 354 to one side of a lamp 355, the other side of thelamps being connected to ground.

ananas@ The-contact arms 311 ofY banks D. are' connected bycofnil monlead 356- to tixedcontact 357 of switch 358, the

contact arm 359 of which is connected to positive main P and the Hcontact of each bank is connected by lead 361 to the 9 contact thereof.Thus, the unit shown in FIG. 12 deines the load director indicator 362.v

The equipment in the illustrative embodiment shown is capable ofplanning the loading of an aircraft having a maximum of sixcompartments, B through G respectively. It is Within the scope `of theequipment to load combinations of such compartments and to this end acompartment selection and control unit 369 is provided.

Thus, referring to FIG. 13, six relays 370 to'375 Vare provided. Each ofthe relays 370 and 375 has ve'niovable Contact arms 376, 377, 378, 379and 380, the contact arm 376'having associated iixed contacts 376', 376;the contact arm 377 having an associated tixed contact 377'; the contactarm 378 having associated xed contacts 378', 37 8; the contact arm 379having associated fixed contacts 379, 379", and the contact arm 380having an associated xed contact 386. The relays 371 to 374 in additionto the contact arms 376 to 380 has an additional contact arm 381 with anassociated xed contact 381.

As shown, the movable contact arms of each of the relays are gangedtogether to move in unison and when the relays are not energized,contact arm 376 engages contact 376"; contact arm 3177 is spaced fromlcontact 377'; contact arm 378 engages contact 378; contact larrn 381 isspaced from contact 381'; contact arm 379 engages contact 379 andcontact arm 380 is spaced from contact 380.

Associated with the relays are ve additional banks of the positionselector switch 48, i.e., banks F, G, H, I, J. Each of said banks has acontact arm 51 and has ten contacts PC, DC, SL, B through G and GC.

One end of the coils 382 of relays 370 through 375 is connected toground and the other end of each of said coils is connected through anassociated lead 383 to the contact arm 384 of a switch 385B-385Gnormally spaced from the associated fixed contact 386 which is connectedto common main 387. One end of main 387 is connected to positive main Pand the other end is connected to the contact arm 51 of bank J of the'posito G and'G to GC are connected through associated di-v odes 392. Thediodes 392 are connected so that current will 110W from the contact GCtoward the contact G, from contact G to Contact F and so on and thediodes 391 are so connected that current will ow from the contacts D, E,F, G and GC to the coil 'of the associated relay but not inethe oppositedirection.

The various` contacts controlled by the relays 370 Y Ythrough 375 areconnected Vto iixed resistors, preferably located in the adaptorV foreach of the aircraft types to be loaded. These resistors are`represented bythe reference numerals RWBI throughV RWGI, RMBl throughRMGl; RWBZ throughV RWGZ and RMBZ through RMGZ. The associated banks ofresistors RW, Y

RM are related to the compartments of the particular Vaircraft* selectedtoY beloaded Which is Ydetermined by the setting of the aircraft typeVswitch 70. Thus, in the illustrative embodiment shownin one position ofthe switch V70 aV circuit willY be completed through the movablecontact.arms Y395 thereof tothe, resistors RWB11- RWGI Vdesignated W2'and'VRMBI-RMGI designated.k

M2, and Yin the other position of the` switch to the resistorsRWB2-RWG2, RMBZ-RMGZ. g

Assuming that the aircraft to be loaded has the fol lowingcharacteristics: a

Chart I Compartment Mavxvinuni Centrold Moment 2, 000 200 400, 000 5,ooo son 1, 500, 00o 5, 000 350 1, 750, 000 4, 000 40D 1, 600, 000 3, 000480 1, 440, 000 l, 000 580 530, 00

Assuming that one inch equals 1 ohm for the centroid; pounds equals lohm for the weight and 1,000 inch pounds equals 1 ohm for the moment,then the resistors RWBl-RWGI; RMBl-RMGI and RBl-RGI will have thefollowing values:

Chart Il Compt Resistors Ohms Resstor- Ohms Resistor Ohms 20 RMBl 400BB1 200 a0 RMCl 1, 50i) RC1 300 50 RMDl 1, 750 RDI 350 40 RMEl 1, 600REI 400 30 RMFI 1, 440 RF1 480 10 RMGl 530 RGl 530 The resistors RWBIthrough RWGI are connected in series with the free end of resistor RWBIconnected to terminal TlW (FIG. 13) and the free end of resistor RWGlconnected to contact 396 engaged by contact arm 395 which is connectedto terminal TZW. There is a xed contact 396 associated `with thejunctions between resistors RWBl and RWCLRWCI and'RWDl, etc. and each ofsuch fixed contacts will bel engaged by the asso ciated contact arm 395when the particular aircraft associated with such resistors, is to beVloaded. The resistors RMB1 through RMGI are connected in a similarmanner.

Thus, as is clearly shown, the free end of resistor RMBl is connected toterminal TIM and the free end of resistor RMG1 is connected to fixedcontact 396 engaged by the contact arm 395 associated with resistor RMGand connected to terminal TZM.

The contact arm 377 of relay 370 is connected by lead 397 to terminalT1W; by leads 397 and 398 to the contact arm 51 of bank I of theposition selector switch 48 and by lead 399 to the fixed contact 376' ofrelay 371. The xed contact 377 of relay 370 is connected by lead 4G-1 tothe fixed contact 376" and contact arm 377 of relay 371; and by leads401, 402 and 403 to contact B of bank H and by leads 402, 404 tothemovable contact arm 395 betweenV resistors RWBl--RWCLY The contact arm37 6 ot' relay 371 is connected by lead 405 to the xed contact 376' ofrelay 372; contact arm 37o of relay 372V is connected to the fixedcontact 376 of relay 373; contact arm 376 of relay 373 is connected tothe Vfixed contact 376 of relay 374 andthe contact arm 376 of relay 374is connected to the fixedV contact 375 of relay 375. The contact arm 376of relay 375 is connected to terminal TSW. Y

VThe fixed contacts 377 of relays 371 through 374' are connected byassociated leads 406, 407, 408ito the'con-V tacts C, D, E and F of bankHofY the position selector switch and also by leads 409 to contact arms395 between resistors RWCL-VRWDI; RWDI-RWEI; RWEI- RWF1; RWF-RWGl andtheV xed contactV 377' of relay v375 is connected by lead 411 toterminal'TZW.

The contact arms 377 'and xed contactr376 of relays 372-375 areconnected together respectively and each is then connected to itsassociatedv lead 407. The contacts B-F of bank H are connected by leads415 to'contactsv CG respectively of bank I, the contact'arm 51 of saidbank H being connected to terminal T4W.

As the circuits for the contact arms 379 and 380 and associated xedcontacts of the relays 370-375 as Well as banks F and G and Atheresistors RMBl through RMG1 is identical to that previously described,no further description thereof* will be made. y

With respect to the additional bank of contact arms 378, 381 andassociated fixed contacts controlling the coil 416 of relay 417, thecontact arm 378 of relay 370 is connected to positive main P, the fixedcontacts 378' and 378" are connected to contact arm 378 and fixedcontact 381 of relay 371. The contact arm 381 and xed contact 378" ofrelay 371 are connected together and connected to tixed contact 381' ofrelay 372 and the fixed contact 378 of relay 371 is connected to thecontact arm 378 of relay 372. These connections are repeated and thecontact arm 381 and fixed contact 378" of relay 374 are connected tofthe fixed contact 378 of relay 375. The ixed contact 378 of relay 374is connected to the xed contact 378 of relay 375 and the movable contactarm 378 of said relay 375 normally engaging said ixed contact 378 isconnected to one end of the coil 416 of relay 417, the other end of saidcoil being connected to ground.

The relay 417 has a contact arm 421 connected to positive main P andnormally spaced from fixed contact 422 connected through lamp 423 toground, the lamp serving as an indication of the last compartment to beloaded.

To ready the equipment for the planning operation the reset switches 187(FIG. 6) of the gross weight accumuiator and programmer 73W, 85W, thegross moment accumulator and programmer 73M, 85M, the remaining weightaccumulator and programmer 73W', 85W and the remaining momentaccumulator and programmer 73M', 85M' are closed. Referring to the grossweight accumulator and programmer 73W, 85W (FIG. 6) which is typical,this will energize reset relay 126 completing a circuit from groundthrough the coil 189, the now closed switch 187, leads 185, y148, 147 topositive main P. Energization of relay 126 will cause the movablecontact arms 127, 128, 129 thereof to engage the associated xed contacts127', 128', 129 to complete a circuit from positive main P through leads147, 148, 185, 191 and the closed contacts 127, 128, 129 of relay 126,leads 193, 194, 195 to the contact arms 112 of cams C-2, C-3 and C-4associated with stepping switches 93, 94 and 95.

If these stepping switches are not at home position at this time, thecontact arms 112 will be engaging the associated fixed contact 113 tocomplete a circuit from positive main P to the Contact arm 107 ofstepping switches 93, 94 and 95 which normally engage the asso-- ciatedixed contact 107', and through the coil 104 of the associated steppingswitch to ground.

As a result, the stepping switches 93, 94, 95 will be energized inconventional manner so that the Contact arms 96, 97, 98 thereof will bemoved step by step until they reach the H or home position at which timethe cams C-2, C-3, C-4 will open the associated cam contacts 112, 113 tobreak the circuit from positive main P thereby stopping further steppingmovement of the stepping switches 93, 94, 95 with the equipment readyfor operation. At this time the reset switches 137 are released. Thegross moment accumulator and programmer, the remaining weightaccumulator and programmer and the remaining moment accumulator andprogrammer which are substantially identical to the gross weightaccumulator and programmer shown in FIG. 6 are reset in similar manner.

' The equipment is now ready to be set for the planning operation.

Atthis time the aircraft selector switch 70 (FIGS. 4, 13) is set to theaircraft type position for which loading is to be planned. As a resultof the setting of the aircraft type switch, referring to FIGS. 4 and 13,the resistors RBI l the third arm of said bridge.

to set 22,700 pounds into the circuit, knobs 26 associated with thehundreds, tens and units switches are set to 2-2-7 respectively.

Referring to FIG. 2 with the switches thus set, the' associated contactarm 25 of banks A, B, C, D and E of the hundreds switch 24 will beengaging the 2 contact of each bank; the contact arm 25 of the tensswitch 23 will be engaging the 2 contact of each bank and the contactarm 25 of the unit switch 22 will be engaging the 7 con-v tact of eachbank. Since each of the resistors in bank E of the units switch 22 has avalue of l ohm, the tens switch l0 ohms and the hundreds switch 100ohms, and one ohm equals pounds, since the resistors of bank E areconnected in series, 227 ohms will be placed in circuit in betweenterminals TRWI and TRW2 proportional to the Weight of 22,700 pounds.

The arm register (FIG. 3) is set to a value proportional to the primarycenter of gravity to the aircraft, i.e., 200 inches from the referencedatum. ToA this end the hundreds switch 44 is set to 2 representing 200ohms; the tens switch 43 is set to 0 representing 0 ohm and the unitsswitch 42 is set to 0 representing 0 ohm. Thus, 200 ohms will beconnected in series between terminals TRAl and TRA2.

Prior to the setting of the weight and arm registers 21 and 41, thecontrol knob 49 of the position selector switch 48 (FIGS. 4 and 13) isset to the first or PC (Primary Condition) position.

As a result, referring to FIG. 4, a circuit will be completed frompositive main P, teminal TRW1, Weight resistor bank 35 of the weightregister 21 which has a value of 227 ohms, terminal TRW2, terminal 54,contact PC 0f bank B of the position selector switch 48 through contactarm 51, lead 77 to junction 79 of bridge B-l so that the resistor bank35 forms one arm of bridge B-l.

As contact arm 51 of Bank C of the position selector switch is engagingcontact PC, a circuit will be completed to junction 79 from negativemain N through the iiXed'resistor 72 which has a value of 100 ohms andthis resistor 72 will form a secondV arm of bridge B-1. The contact arm51 of bank E of the position selector switch,` which is now engagingcontact PC, will complete a circuit from negative main N, lead 66,terminal TRAl, arm resistor bank 45 of the arm register 41 which has avalue of 200 ohms, terminal TRAZ, terminal 65, lead 64, contact arm 51,lead 82'to junction 81 of bridge B-1 to form 'Ihe fourth arm of thebridge is dened by the series connected balancing resistors 225 of bankF of multiplier A balancing unit 210, one end of which is connected tojunction `81 through lead 228, terminal 84 and lead 83 and the other endof which is connected through lead 232 to position main P.

The fourth arm of bridge B-1 is the balancing arm, the setting of whichis controlled by the actuation of the stepping switches 212, 213, 214.As previously described a phase sensitive'ampliiier 80 of conventionaltype is connected between junctions 79 and 81 and the output of thephase sensitive amplifier through the multiplier A programmer 217controls the stepping switches 212, 213, 214 to determine the setting ofthe series connected resistors in bank E. v

At this time the bridge B-1 has in one arm resistors 35 of value of 227ohms related to a weight of 22,700 pounds. The second arm has a resistor72 having a value of 100 ohms. The third arm has resistors 45 having avalue of 200 ohms proportional to the primary senesi 19 center ofgravity of 200 inches and the fourth arm has the multiplier A balacingresistors 225 which will be set to balance the bridge in the followingmanner.

The manual start switch S shown in FIGS. l and 5, is closed to energizethe multiplier A programmer. As a result, the multiplier A programmer217, rst homes the stepping switches 212, 213, 214 (FIG. in conventionalmanner so that all of the contact arms 215 thereof are set to position Hor home position which is tied to position 9 and the resistors of banksF` of the stepping switches, which are connected in series, haye a valueof 999 ohms (each resistor R-l in the unit switch 212 `has a value of 1ohm, each resistor R-10 in thertens switch 213 has a value of ohms andeach resistor R-100 in the hundreds switch 214 has a value of 100 ohms).The programmer 217 then automatically steps the hundreds switch 214 tothe 0 position at which time there will be only 99 ohms in circuit.Thereupon, the programmer 217 connects the output of the phase sensitiveamplier 80 to actuate the hundreds stepping switch 214.

Since at this time we have 227 ohmsin one arm of the bridge, 100 ohms ina second arm and 200 ohms in the third arm, for the bridge B-1 to be inbalance, the Vfourth arm or balancing resistors bank 225 must have avalue of 454,ohms. Since the hundreds switch-214 has been stepped to 0,the resistor bank 225 has a valueof 99 ohms and the bridge B-1 is not inbalance. Hence, pulses delivered by the phase sensitive amplifier 80will cause the hundreds stepping vswitch 214 to increase the resistancevalue of the hundreds resistors in steps of 100 ohms until there iseither a balance or a phase reversal of the signal voltage from thebridge, i.e., if the value ofthe multiplier A resistance equalsorexceeds 45,4 ohms. For example, when the hundreds switch 21,4 ispulsed to contact 4 the resistor bank 225 will have a value of 499 ohmswhich exceeds the desired value of 454 ohms, thereby causing phasereversal in the amplier. At this time no further pulses will bedelivered to the hundreds stepping switch 214.

Through the multiplier A programmer 217 the tens switch 213 is steppedto 0. At this time there will be 409.0hrns in resistor bank 2-25 whichis less than the desired balancing value of 454 and the phase sensitiveamplier 80 through the programmer 217 will now pulse the ,tens switch213 to contact 5. .At this time there again will be a phase reversal inthe amplifier 80, since the resistor bank 225 will have a value of 459ohms in excess of the desired value of 454. Again no further pulses willbe delivered to the tens switch 213Jand theY multiplier A programmer 217will move the units switch 212 to 0' position. Thus there will be 450ohms in the resistorbank 225 and the Vprogrammer 217 will connect theamplilier 80 to deliver pulses 'to the units stepping switch 212 andwhen such stepping switch reaches the 4 position, at which time theresisto'r'bank 225 will have a value of V454'ohms, the bridge B1` willbe in balance programmer" are substantially identical except' vfor theresistors R-l, R-10 and R-100 which in the'vcase' of the remainingmoment and gross moment accumulatorshave a value of 10, 100 and 1,000ohms respectively rather than l, l0 and 100 ohms, only the operationofthe gross weight accumulator and programmer shown in FIG. 6 will bedescribed in detail.

As previously described, after the primary condition .balancingoperation is completed, the multiplier A pro-y grammer 217 is cycled toready the equipment for the next operation which is the setting of thegross weight, the gross moment and the remaining moment accumulators.

The add switch 154 of each of the units 85W, 73W; 85M, 73M; and 85M',73M is closed momentarily and the multiplier A programmer 217automatically closes the start switch 137 (FIG. 7) of each of said unitsmomentarily. Referring to FIG. 6,` a circuit will be completed frompositive main P lead 141 through the closed start switch 137 to the Hcontact of bank A of stepping switch 91, contact arm 92, through thecoil 102 of switch 91 to ground. Since the start switch 137 is closedonly momentarily, upon opening thereof, the contact arms 92 of banks A,B,-C and D of stepping switch 91 move from H to 1 position inconventional'manner. When stepping switch 91 was momentarily energizedits associated contacts 105, -105' and 106, 106 closed and openedrespectively.

When contacts 105,V 105 closed, a circuit was completed from positivemain P, leads 147, 146 through the coil 145 of time delay relay 13110ground to open the normally closed contacts 132, 132 of said relay. Whencontacts 105, 105 open, although the circuit to relay 131 is broken, itscontacts 132, 132' do not close, for a switch 91, contact arm 92 throughcoil 102 to ground and of the aircraft of 22,700 pounds and the primarycenter i of gravity of 200 inches. At this time the primary rnoment of4,540,000 inch pounds has been determined by the Vsetting of theresistor bank 225 and the weight re-v Y e VAsthe construction of `thegross weight accumulator andV programmer, the gross moment accumulatorand programmer and remaining moment accumulator and the cycle abovedescribed is repeated. Thus, the contact arms 92 of banks A, B, C and Dof stepping switch 91 move from contact to Contact at a time intervalbased upon the setting of time delay relay 131. This operation continuesuntil the contact arm 92 of bank Avof stepping switch 91 gets back to Hposition at which time it is connected to the now open start switch 137and the cycling stops.

During the operation of the stepping switch 91 with each de-energizationthereof it closed the circuit from positive main P through lead 147,contacts 106, 106' to junction X, and thence through lead 15,2, closedcontacts 153, 156 of switch 154, lead l1 58 to terminals TAU, TAT andTAH of the weight register '21 shown Vin FIG. 2.

As previously described, sincethe contact arms 25 of the banks of thehundreds, units and tens switches .24, 23, 22 of the weight register 21at at positions 2-2-7 respectively, the terminal TAH will be connectedto terminal 'TI-I2; the terminal TAT will be connected kto terminal TT2and the terminal TAU will be connected to terminal TU1, TU2 and TU4.VHence, referring .to FIG. 6, positive main P is connected to Vsuchterminals TH2, TT2 and TUI, TU2 and TU4 intermittently with each'movement of stepping switch 91. Y

As previously described, the contact arms 92 of banks I A to D ofstepping switches 91 (FIG. 6) are ganged together. Hence, when thecontact arm 92 of bank B of switch 91 reaches contact 2 `(the switch 162being opened by the programmer 217 at this Vtime so that the` engagementof contact 1 by the contact arm 92 ofbank Bfwill have no effect), thestepping switch 93 will be energized.-

switch 91 completes its cycle and as the contact arm 92.

of bank B of'switch 91 cycles from position 2 past position 8, 7 pulseswill be delivered from terminals TU1, TU2,'TU4 to the coil 104 ofstepping switch 93 due to the setting of the units switch 22 of theWeight register 21 and its contact arms 96 and 97 will be moved tocontact 7. As the contact arms 92 of banks C and D of stepping switch 91sweep from contacts H through contact 14, contacts 3 and 4 of bank C ofswitch 91 will be connected to positive main P through terminal TF2 andcontacts 3 and 4 of bank D of switch 91 Will be connected topositivemain P through terminal TH2 due to the setting of the tens and hundredsweight switches 23, 24 of the weight register. Hence, two pulses will bedetermined from terminals 'IT2 and TH2 to the coils 104 of the steppingswitches 94 and 95 and the contact arms 96, 97, 98 of each said steppingswitches will be moved to contact 2. At this time there will Ibe 227ohms connected in series in the resistor bank 203 between terminals TRSand TR4 of the gross weight accumulator (FIG. 5) which is proportionalto a weight of 22,700 pounds and the position of the weight register hasbeen duplicated in the setting of the gross weight accumulator resistors203.

As the contact banks B, C, D, E and F of the multiplier A balancingswitches 212, 213, 214 (FIG. 5) correspond to the banks A, B, C, D and Eof the weight register 21, in a similar manner, the gross momentaccumulator 73M will be set to contacts 4, 5, 4 (hundreds, tens, units)corresponding to a moment of 4,540,000 inch pounds.

Similarly, the remaining moment accumulator 73M which is connected inparallel with the gross moment accumulator 73M will have the contactarms 96, 97 of its stepping switches 93, 94, 95 (FIG. 7) set to contacts4, 5, 4.

The remaining moment accumulator (FIG. 7) diters only from the grossweight accumulator (FIG. 6) in the connections of the resistors in bankA and the value of resistors R-1, R- and R-100. Thus, with the contactarm 96 of bank A (FIG. 7) at contacts 4-5-4, five resistors R-100; fourresistors R-10 and tive resistors R-l will be in series to provide thecomplement of nine.

Thus, when the switches are set to contacts 4-5-4 the resistance betweenterminals TR3, TR4 of the remaining moment accumulator (FIG. 7) willhave a value of 5,450 ohms, the complement of 9-9--9 for 4-5-4.

At this time the multiplier A programmer has cornpleted the cycle forthe primary condition setting of the position selector switch 4S and thegross weight, the gross moment and remaining moment accumulator havebeen setto 227 ohms 22,700 pounds), 454 ohms (4,540,000 inch pounds) and5,450 ohms (the complement of 9 for 4,540 ohms or 4,540,000 inchpon-uds) and ythe equipment is ready for the next step in the cycle ofoperation.

The add switches 154 are now opened and in the next step of operationthe position selector switch 48 is turned to DC or desired condition. y

Assuming that a cargo weight of 9,300 pounds is to be carried and thedesired final take-ofi center of gravity is to be 240 inches, the weightregister switches 24, 23, 22 (FIG. 2) are set to contacts 0-9-3,respectively or 93 ohms representing a weight of 9,300 pounds and thearm register switches 24, 23, 22 are set to contacts 2-4-0 respectivelyor 240 ohms representing an arm of 240 inches.

The bridge B1 (FIG. 4) now has in one arm the Weight resistors 35 fromthe weight register 21 which have a value of 93 ohms related to thedesired cargo Weight of 9,300 pounds and in series therewith the weightresistance 203 from the gross weight accumulator 73W previously set to227 ohms representing the primary weight of 22,700 pounds. Consequently,this arm of the bridge has 320 ohms in circuit representing a weight of32,000 pounds connected in seriesrbetween positive main P and 22junction ,79. This total weight of 32,000 pounds is the desired grosstake-oli weight.

The resistor 72 which has a value of 100 ohms is also connected tojunction 79 to form a second arm of bridge B1. 'The arm registerresistors 45 which have a value of 240 ohms related to a desiredtake-off center of gravity of 240 inches is connected to junction 81 ofthe bridge B-1 4to form a third arm, and the multiplier A balancingresistors 225 of bank E connected to junction 81 are the fourth arm ofthe bridge.

Since 320 ohms is in one arm of the bridge proportional to a weight of32,000 pounds and 240 ohms in the second arm of the bridge related tothe center of gravity of 240 inches and since the fixed resistor 72 hasa value of l0() ohms, for the bridge B-1 to balance the multiplier Aresistor 225 of bank E must have a value of 768 ohms, proportional to adesired take-off moment of 7,680,000 inch pounds.

As previously described, the multiplier A programmer 217 is actuated byclosing the manual start switch S (FIG. 1) and the stepping switches212, 213, 214 are cycled by the multiplier A programmer 217 yto homeposition, placing resistors in circuit of a value of 999 ohms aspreviously described. Thereupon, the multiplier A programmer 217 cyclesthe hundreds switch 214 from home to 0 position so that a total of 99ohms is now in.

circuit. As previously described, the output of the phase sensitiveamplier will control the cycling of the stepping switches 214, 213, 212until they are set to contacts 7, 6, 8 or 768 ohms proportional to avalue of 7,680,000 inch pounds which will balance the bridge B1.

At this time the subtract switches y of the accumulators 73W, 73M, 73W',73M are closed (see FIG. 6 for typical circuit).

Since the subtract switch 155 (FIG. 2) of the remaining momentaccumulator is closed and since the switches (FIG. 5) 214, 213I and 212are set to contacts 7-6-8, the terminal TSH is connected through the 7vcontact of bank B of switch 214 to terminal THS of the remaining momentaccumulator (FIG. 6) terminal TST is connected through the 6 contact ofbanks B and E of switch 213 to terminals 'ITS and TTI and the terminalTSU is connected through the 8 contact of bank E of switch 212 toterminal TUI.

Since the remaining moment accumulator switches 95, 94, 93 (FIG. 7) havepreviously been set to the primary moment, i.e., contacts 4-5-4 and asnormally closed switch 4162 (FIG. 6) is opened by the multiplier Aprogrammer 217 in the DC or desired condition position of the positionselector switch 48, as switch 91 cycles, one pulse is delivered fromterminal TUI to switch 93, 3 pulses lfrom terminals Tl`1, 'ITS to switch94, and 2 pulses from terminal THS to switch 95, the contact arms 96(FIG. 6) of switches 93, 94, 95 will be moved to contacts 5, 8, 6.

As contact arm 96 of switches 93, 94, 95 of the remainingrrnomentaccumulator (FIG. 7) are at position 5-8-6 respectively, resistance of-40 ohms, 100 ohms and 3,000 ohms is connected in series for a total of3,140 ohms, between terminals TRS, TR4 of the remaining momentaccumulator. Thus as 7,680,000 inch pounds is the desired gross take-offmoment and 4,540,000 inch pounds was the primary moment, the diterenceor remaining moment is 3,140,000 inch pounds represented by 3,140 ohmsor 5--8-6.

Since the remaining Weight programmer and accumulator 85W', 73W had`been originally set to home position by the action of the associatedreset switch 187, and the weight register switches 24, 23, 22 (FIG. 2)are at position 0--9-3 (i.e. 93 ohms) vfor a weight of 9,300 pounds, andsince the unit switch 22 is at 3 contact the terminal TSU will beconnected to terminals TU4, TUS. Since the tens switch 23 is Aat 9position, terminal TSI will Abe open circuited. Since the hundredsswitch 24 is

